Collins Aerospace Museum

233D Transmitter Restoration Project

Applied power to the filament circuits on the exciter chassis and the 813, 807 and 837 all light and there appears to be no problem. The 6X5 rectifier in the “Keyer” circuit does not light and the associated 6SJ7 “Keyer” tube has been replaced by a plug-in relay. Obvious wiring changes on the 6SJ7 socket, so that needs to be investigated.

That completes all of the power supply check outs except for the big plate transformer. Rod thinks we can check out the big transformer by applying 208 to each of the primary windings and check the outputs with my Jennings voltmeter. I had some repairs to make on the voltmeter but it appears to be working now, so I’ll bring it on Monday.

I have started tearing down the HV rectifier and the Bias chassis to get them ready for chrome plating. I need to check that the wiring to the Modulator tube deck is correct and then I will tear down that chassis. Quality plating in Sterling, IL estimates that each chassis will cost $150 to re-plate. They need 6 to 8 weeks, so we need to get them over to Sterling in the next week or so. Anyone headed that way could drop them off, but it is a nice drive and I probably should be there to make sure we have an understanding.

Charley Snodgrass has agreed to publish any wants or requests for help on the CARC mail list. I’ll finish up the list of needed parts by Wednesday, but I will wait until after Dayton to ask for help. I’m still in “shotgun” mode, but I’m planning to spend the next two weeks focusing.

I haven’t made any attempt to look at the modulation transformer. Haven’t done anything with big AM for at least 40 years, so any suggestions appreciated.

I did find the schematic for the phone relay assembly, so we have something to work with.

The Starship project appears to be getting started. The 3 bay rack in the front of the room will need to be moved back to the simulator. We need to move the 3 8040 antenna couplers into the store room so there is more room. Larry will try to get the IT folks to move the two skids of equipment out of the room.

Larry is also exploring antenna locations/connections.

Chad Todd moved a rack into our “storage” area, so we can maybe use it to setup an HF-80 system as a backup and to house a receiver? Doesn’t have rollers.

Three-phase power is still a major concern. Suggest we get the electricians to take the cover over the distribution box, to see if the 3-pole breakers have wires connected. I doubt that it will be all that hard to pull new wires, but if the wires are still under the floor, it should be pretty easy to hook things up.

My early predictions on schedule may not be as unlikely as I thought! Lots to do, but we are making headway.